Structure and method of making magnetic cards

ABSTRACT

A single plastic sheet is formed from a number of sheets that include a central core sheet having a plurality of windows, in each of which is a strip of magnetic material of the thickness thereof. The core sheet is first tacked to an opaque sheet, upon which the magnetic strips are laid when placed in the windows. The a second opaque sheet is placed over the core sheet, and clear sheets on which desired information is printed are placed on the opaque sheets. All the sheets are fused into a single sheet with the strips embedded therein, and is then cut into individual cards having respective strips at the same locations there into facilitate encoding and acceptance in an appropriate reader.

ay D. c. KRAMER 3,811,977

STRUCTURE AND METHOD OF MAKING MAGNETIC CARDS Filed April 17, 1972 United States Patent 3,811,977 STRUCTURE AND METHOD OF MAKING MAGNETIC CARDS David C. Kramer, Redondo Beach, Calif., assignor to Rusco Industries, Inc., Los Angeles, Calif.

Filed Apr. 17, 1972, Ser. No. 244,488

Int. Cl. B32b 31/00; Gllb 5/ 80 US. Cl. 156-108 Claim ABSTRACT OF THE DISCLOSURE A single plastic sheet is formed from a number of sheets that include a central core sheet having a plurality of windows, in each of which is a strip of magnetic material of the thickness thereof. The core sheet is first tacked to an opaque sheet, upon which the magnetic strips are laid when placed in the windows. Then a second opaque sheet is placed over the core sheet, and clear sheets on which desired information is printed are placed on the opaque sheets. All the sheets are fused into a single sheet with the strips embedded therein, and is then cut into individual cards having respective strips at the same locations thereinto facilitate encoding and acceptance in an appropriate reader.

BACKGROUND OF THE INVENTION (1) Field of the invention This invention relates to methods of making magnetic identification cards, credit cards and the like.

(2) Description of the prior art It is known to form cards of magnetic material. See, for example, US. Pat. No 3,444,711, which discloses a homogeneous magnetic strip that is coded by spot magnetizing it at selected areas. Such a strip is typically formed of barium ferrite distributed throughout a rubber-like base. The strip is rather limp even where it is relatively thick, e.g., 0014-0020 in. To form a relatively stiff card incorporating such material, the strip is located between plastic strips of the same length and width, and the three are bonded together, e.g., as with a suitable adhesive and/ or by heating them under pressure.

Attempts at quantity production of such cards are frustrated by myriad problems. If they are put together with adhesive alone, many rejects result from nonuniformities in bonding. Where they are heated under pressure, the magnetic strip undergoes nonuniform changes in thickness, as manifested by its edge portions being extruded paste the edges of the stack, and variations in thickness throughout the card after such exposed portions are trimmed away. And in either case, the laminations are readily separable over extended use, and may readily be purposely separated.

SUMMARY OF THE INVENTION This invention embraces a method of producing magnetic cards in quantity, wherein a plurality of magnetic strips are located in windows of a plastic core sheet of the same thickness as the strips, and seated against an opaque plastic sheet, to which the core sheet is tacked, placing another opaque plastic sheet on the core sheet, fusing said sheets to form a single plastic sheet, and cutting the single sheet to form a plurality of cards, each with a respective magnetic strip therein. This invention also embraces the steps of placing clear plastic sheets with selected printing thereon against the opaque sheets prior to fusing, whereby the final single sheet includes top and bottom surfaces on which desired information is visible.

3,81 1,977 Patented May 21., 1974 ice FIG. 1 is an exploded view of plastic sheets;

FIG. 2 is a fragmentary perspective view of the center sheet of FIG. I placed on the adjacent opaque sheet, and showing windows in the center sheet in which strips of magnetic material are placed;

FIG. 3 is a fragmentary perspective view of the sheets assembled for fusing;

FIG. 4 is a fragmentary perspective view of the single plastic sheet with embedded magnetic strips resulting from fusing the stack of sheets of FIG. 3; and

FIG. 5 is a top plan view of a card cut from the sheet of FIG. 4, and illustrating locations of magnetized spots which contain the card code.

DESCRIPTION OF PREFERRED EMBODIMENT Referring to FIGS. 1 and 2, a core sheet 10 has a plurality of openings, shown as windows 12, which preferably are simultaneously formed therein in a suitable punching operation. In one example, such a sheet 0.017 in. thick is provided with seventy-two identical rectangular windows 2.225 in. x 1.0.25 in. arranged in nine rows. Thus arranged, the ends of adjacent windows are 1.275 in. apart, and the longitudinal edges of adjacent windows are 1.225 in. apart.

The sheet 10 is placed on an opaque sheet 14, and the two are fused together at selected spots, analogous to tack-welding, by spot heating. Then strips 16 of homogeneous magnetic material are laid in the windows and on the sheet 14, such strips being of the same thickness as the sheet 10 and dimensioned to fill the windows.

Placed on the sheet 10 is an opaque sheet 18 of the same thickness as sheet 140.005 in. in the present example. Sheets 10, 14, 18 are then placed between sheets 20, 22, which in this example are transparent, thin (0.0015 in.), and on which desired information is printed. The sheets 10, 14, 18, 20, 22 are all plastic sheets adapted when heated sufiiciently to fuse together into a single sheet 30 (FIG. 4). For example, using Tenneco VLH5195-5 rigid vinyl for sheets 20, 22, VCLU1141 rigid vinyl for sheets 14, 18 and VLH5765 rigid vinyl for the center sheet 10, the single sheet 30 results from bringing the temperature of the stack up to approximately 300 F. over a predetermined period of time, e.g., 7-9 minutes, at which point heating is discontinued and the fused sheet 30 is returned to room temperature over a predetermined period, e.g., 5-7 minutes. Heating and cooling times will vary in accordance with the amount and number of colors of ink on the sheets 20, 22. For a particular arrangement, it is necessary initially to determine the specific heating and cooling cycle by trial and error. Equipment used for this purpose may be a conventional steam press with platens between which the stack of sheets to be fused are placed between polished chrome plates, as in forming conventional credit cards.

The single sheet 30 will be seen in FIG. 4 to be one in which the printed matter is all that is visible. In this example, the matter shown includes the name of the issuing entity spaced along the sheet, as well as spaced arrows together with the legend To Reader. The sheet 30 is suitably indexed and cut lengthwise and across to form individual cards 40 (FIG. 5) in each of which the strip 16 and printed data are in the same position.

Referring to FIG. 2, dotted lines illustrate cuts adjacent one longitudinal edge and one end of each strip 16. Referring to FIGS. 4 and 5, each individual card thus cut from sheet 30 is trimmed to form the finished card 40, which in this example is 3.5 in. long and 2.25 in wide, and has the top longitudinal edge of the strip 16 approximately 0.100 in. from the top card edge, and the left end of the strip 0.200 in. from the left edge of the card. Thus finished, all cards also hear the printed data in the same positions.

The card 40 is coded when issued. In FIG. 5, dotted spots 42 illustrate portions where the strip is magnetized along lines perpendicular to the card faces. In this connection, the card is preferably inserted in an encoder device that is adapted to magnetize all such spots without changing the position of the card. As desired, all cards may have the same polarity distributions, i.e., have the same code, or each may be coded diiferently than all others by virtue of a polarity distribution that is ditferent from all others.

A code detector or reader for such cards typically has a slot in which such a card is inserted pursuant to instructions printed thereon, e.g., in the direction of the arrow and with that surface nearest the user. Respective card spots align with sensors in the reader, and a circuit in which the sensors are connected is operable to signify that the spot fields are correctly oriented.

For magnetic cards made in accordance with this invention, it will be noted that the magnetic strips 16 remain the same thickness through out the steps of the method of this invention. After stacking the various sheets as described, the strips are confined within the borders of the windows 12. They remain confined as the fused sheet 30 is formed, i.e., no extrusion or other deformation can occur. Since the finished card is a single plastic body in which the strip is embedded, separation of the strip from the body cannot occur from normal use. Thus, this invention permits quantity production of magnetic cards of uniform dimensions and structural and magnetic characteristics.

What is claimed is:

1. The method of forming and coding cards of identical structure comprising the steps of:

providing a first plastic sheet with a plurality of identical windows therein;

placing said first sheet on a second plastic sheet that is opaque;

heat tacking said first and second sheets together; placing a respective flexible strip of magnetic material in each window and in surface-to-surface contact with said second sheets,

each strip being of a thickness no greater than the thickness of said first sheet; placing a third opaque sheet of plastic over said first sheet; placing a fourth sheet of plastic having an indicium printed thereon at each of a plurality of locations,

the number of such locations being equal to the number of windows in said first sheet; heating the stacked sheets to fuse them into a single plastic sheet with the strips embedded therein; cutting said single sheet to form a plurality of cards of identical dimensions each with a respective strip embedded therein and a respective indicium thereon,

the indicium being a visual aid showing the direction and orientation of the card for insertion in encoding or reading devices; and inserting each card in an encoding device and operating said device to magnetize the strip embedded in the card at a plurality of spots poled perpendicular to the card faces.

References Cited UNITED STATES PATENTS 2,588,067 3/1952 Whitehead 156-306 3,505,139 4/1970 Wentworth 156-250 3,068,140 12/1962 Biddle 156250 3,264,154 8/1966 Kiehl 156-108 3,177,106 4/1965 Seefluth et al. 156-250 DOUGLAS J. DRUMMOND, Primary Examiner US. Cl. X.R. 

